Energy release rates for interlaminar delamination in laminates considering transverse shear effects

This paper presents simple and closed-form formulas for calculating mode I and II energy release rates, GI and GII, of a straight interlaminar crack in composite laminates subjected to general loadings. In addition to general combination of geometrical dimensions and material properties, the formulas are also explicitly expressed in terms of generic stress resultants in the cross section at the crack tip. The energy release rates predicted by the present analytical solutions are compared with those in the literatures. The novel formulations are presented and the simple closed-form solutions are obtained in terms of a general material and geometry combination and arbitrary loadings as well as the interface deformations.